Polkadot is indeed a great project offers something quite unique, but I doubt if Polkadot is the real Ethereum killer, because if it is true then it should be having higher marketcap than Binance Smart Chain now, if you go on CoinMarketCap site you will see that bnb is among the top 3 coins now, since it simply solves the basic problems people have with Ethereum Network which are high gas fees and slow transactions, although BSC is a copycat of Eth network with some features, I think there's a possibility of bnb reaching eth if the ETH 2.0 won't be out in the next 2years,so for me BSC is eth killer.
you are right, I think it is like that too. BNB is the closest and most potential asset at the moment when we look at the increasing popularity of BNB. It's just a matter of waiting for the capitalization of BNB to continue to increase, even though it is still too far from ETH.
this situation could have gotten even closer when ETH did not immediately resolve their problem of exorbitant transaction fees. BNB by launching the BSC is already very popular nowadays and is a good solution for traders.